Dithiinopyridazinone Derivatives

ABSTRACT

The present invention relates to new dithiinopyridazinedione derivatives, to processes for preparing them, to their use for controlling unwanted microorganisms, more particularly phytopathogenic fungi, in crop protection, in the household and hygiene sector and in the protection of materials, and also to crop protection compositions comprising these dithiinopyridazinedione derivatives.

The present invention relates to new dithiinopyridazinedione derivatives, to processes for preparing them, to their use for controlling unwanted microorganisms, more particularly phytopathogenic fungi, in crop protection, in the household and hygiene sector and in the protection of materials, and also to crop protection compositions comprising these dithiinopyridazinedione derivatives.

Various dithiinopyridazinedione derivatives have already been disclosed as fungicides (cf. WO 95/29181, U.S. Pat. No. 4,150,130) but no diones.

In view of the constantly increasing environmental and economic requirements imposed on modern fungicides, in terms, for example, of activity spectrum, toxicity, selectivity, application rate, formation of residues, and favourable producibility, and in view of the fact, moreover, that problems with resistances, for example, may occur, a continual task is to develop new fungicides which more effectively meet the stated requirements in certain areas at least.

The present invention now relates to new dithiinopyridazinedione derivatives of the general formulae (I)

in which

-   R¹ and R² either simultaneously are cyano or together are the group     —C(═O)—N(R⁵)—N(R⁶)—C(═O)—, whereby the compounds of the formula (I)     comprise a second pyridazinedione ring, -   R³, R⁴, R⁵ and R⁶ are identical or different and are hydrogen, are     C₁-C₈-alkyl optionally substituted one or more times by halogen,     —OR⁷ and/or —OR⁸, are C₁-C₈-alkoxy, C₁-C₈-alkylthio,     C₁-C₈-haloalkoxy, C₁-C₈-haloalkylthio, C₁-C₄-alkylamino,     di-(C₁-C₄-alkyl)amino or phenylsulfonylamino, C₃-C₇-cycloalkyl     optionally substituted one or more times by halogen, C₁-C₄-alkyl or     C₁-C₄-haloalkyl, or are aryl or aryl-(C₁-C₄alkyl) each optionally     substituted one or more times by halogen, C₁-C₄-alkyl,     C₁-C₄-haloalkyl, C₁-C₄-alkoxy or —OR⁸, -   R³ and R⁴ also together are C3-C5-alkylene (alkanediyl),     C₃-C₆-alkoxyalkylene or C₃-C₆-alkylthioalkylene, -   R⁵ and R⁶ also together are C3-C5-alkylene (alkanediyl),     C₃-C₆-alkoxyalkylene or C₃-C₆-alkylthioalkylene, -   R⁷ is hydrogen, C₁-C₄-alkyl or C₁-C₄alkylcarbonyl or is aryl     optionally substituted one or more times by halogen, C₁-C₄-alkyl or     C₇-C₄-haloalkyl, and -   R⁸ is hydroxyl, C₁-C₄-alkyl or C₁-C₄-alkoxy.

Dithiinopyridazinedione derivatives of the formula (I) of the invention are very suitable for controlling unwanted microorganisms, more particularly phytopathogenic fungi. The abovementioned compounds of the invention can be used in crop protection, in the household and hygiene sector, and in the protection of materials.

A general definition of the dithiinopyridazinedione derivatives of the invention is provided by the formula (I). Preferred dithiinopyridazinedione derivatives of the formula (I) are those in which the radicals have the definitions below. These preferred definitions apply equally to the intermediates in the context of the preparation of compounds of the formula (I).

R¹ and R² preferably simultaneously are cyanor.

R¹ and R² also together preferably are the group —C(═O)—N(R⁵)—N(R⁶)—C(═O)—.

-   R³, R⁴, R⁵ and R⁶ are preferably identical or different and     preferably are hydrogen, are C₁-C₆-alkyl optionally substituted one     or more times by fluorine, chlorine, bromine, —OR⁷ and/or —OR⁸, arc     C₁-C₆-alkoxy, C₁-C₆-alkylthio, C₁-C₆-haloalkoxy,     C₁-C₆-haloalkylthio, C₁-C₃-alkylamino, di-(C₁-C₃-alkylamino or     phenylsulfonylamino, are C₃-C₇-cycloalkyl optionally substituted one     or more times by chlorine, methyl or trifluoromethyl, or are phenyl     or phenyl-(C₁-C₄-alkyl) each optionally substituted one or more     times by fluorine, chlorine, bromine, methyl, trifluoromethyl or     methoxy, where R³ and R⁴, and R⁵ and R⁶, are not simultaneously     phenyl or phenyl-(C₁-C₄-alkyl). -   R³, R⁴, R⁵ and R⁶ are more preferably identical or different and     more preferably are hydrogen, are methyl, ethyl, n-propyl,     isopropyl, n-, iso-, sec- or tert-butyl each optionally substituted     one or more times by fluorine, chlorine, hydroxyl, methoxy, ethoxy,     methylcarbonyloxy and/or carboxyl, are methoxy, ethoxy, methylthio,     ethylthio, trifluoromethoxy, trichloromethoxy, trifluoromethylthio,     trichloromethylthio, methylamino or dimethylamino, are     C₃-C₇-cycloalkyl optionally substituted one or more times by     chlorine, methyl or trifluoromethyl, or are phenyl, benzyl,     1-phenethyl, 2-phenethyl or 2-methyl-2-phenethyl each optionally     substituted one to three times by fluorine, chlorine, bromine,     methyl, trifluoromethyl or methoxy, where R³ and R⁴, and R⁵ and R⁶     are not simultaneously phenyl, benzyl, 1-phenethyl or 2-phenethyl. -   R³, R⁴, R⁵ and R⁶ are very preferably identical or different and     very preferably are methyl, ethyl, n-propyl or isopropyl, are     methoxy, methylthio, trifluoromethoxy, trichloromethoxy,     trifluoromethylthio or trichlorome-thylthio, are cyclopropyl or     cyclohexyl each optionally substituted by chlorine, methyl or     trifluoromethyl, or are phenyl or benzyl each optionally substituted     one to three times by fluorine, chlorine, bromine and/or methoxy,     where R³ and R⁴, and R⁵ and R⁶, are not simultaneously phenyl or     benzyl. -   R³ and R⁴ also together preferably are —(CH₂)₃—, —(CH₂)₄—, —(CH₂)₅—,     —(CH₂)₂—O—(CH₂)₂— or —(CH₂)₂—S—(CH₂)₂—. -   R⁵ and R⁶ also together preferably are —(CH₂)₃—, —(CH₂)₄—, —(CH₂)₅—,     —(CH₂)₂—O—(CH₂)₂— or —(CH₂)₂—S—(CH₂)₂—. -   R⁷ preferably is hydrogen, methyl, ethyl, methylcarbonyl or     ethylcarbonyl or is phenyl optionally substituted one or more times     by fluorine, chlorine, methyl, ethyl, n-propyl, isopropyl or     trifluoromethyl. -   R⁷ more preferably is hydrogen, methyl or methylcarbonyl or is     phenyl. -   R⁸ preferably is hydroxyl, methyl, ethyl, methoxy or ethoxy. -   R⁸ more preferably is hydroxyl or methoxy.

One embodiment of the dithiinopyridazinedione derivatives of the invention can be described by the formula (I-a):

in which R³ and R⁴ have the definitions indicated above.

One embodiment of the dithiinopyridazinedione derivatives of the invention can be described by the formula (I-b):

in which R³, R⁴, R⁵ and R⁶ have the definitions indicated above.

Specifically, reference may be made to the compounds identified in the preparation examples.

The dithiinopyridazinedione derivatives which can be used in accordance with the invention may optionally be present as mixtures of different possible isomeric forms, in particular of stereoisomers, such as E- and Z-, threo- and erythro-, and also optical isomers, for example, but also optionally of tautomers. The E- and the Z-isomers, and also the threo- and erythro-isomers, and also the optical isomers, any desired mixtures of these isomers, and also the possible tautomeric forms are claimed.

Dithiinopyridazinedione derivatives of the formula (I-a) may be prepared by reacting

(a) pyridazinedione derivatives of the formula (II)

-   -   in which R³ and R⁴ have the definitions indicated above,     -   with disodium 1,2-dicyanoethene-1,2-bis(thiolate) of the formula         (III)

-   -   optionally in the presence of a diluent (e.g. tetrahydrofuran,         water or mixtures thereof)

Dithiinopyridazinedione derivatives of the formula (I-b) may be prepared by reacting

(b) pyridazinedione derivatives of the formula (II)

-   -   in which R³ and R⁴ have the definitions indicated above,     -   with thiourea of the formula (IV)

-   -   optionally in the presence of a diluent (e.g.         dimethylformamide).

A general description of the pyridazinedione derivatives required as starting materials when carrying out processes (a) and (b) according to the invention is given by the formula (II). In this formula, R³ and R⁴ have the above-indicated preferred, more preferred and/or very preferred definitions.

Pyridazinedione derivatives of the formula (II) are known or can be obtained in a known way. They may be prepared, for example, by reacting

(c) hydrazine derivatives of the formula (V)

in which R³ and R⁴ have the definitions indicated above, with dichloromaleic anhydride of the formula (VI)

optionally in the presence of a diluent (e.g. water).

The disodium 1,2-dicyanoethene-1,2-bis(thiolate) of the formula (III), also required as a starting material when carrying out process (a) of the invention, is known. It is also possible to use the compound of the formula (HI) in the form of a salt or of a hydrate (e.g. in the form of the dihydrate). The compound of the formula (HI) can be used in (E) or (Z) form.

The thiourea additionally required as starting material when carrying out process (b) of the invention is known. Alternatively, other sulphurizing agents as well, such as sulphides, exemplified by sodium sulphide, thiosulphate, exemplified by sodium thiosulphate, and hydrogen sulphate may be used.

A general description of the hydrazine derivatives required as starting materials when carrying out process (c) of the invention is given by the formula (V). In this formula, R³ and R⁴ have the above-indicated preferred, more preferred and/or very preferred definitions. Hydazine derivatives of the formula (V) are known. It is also possible to use hydrazine derivatives of the formula (V) in the form of a salt (e.g. as hydrochloride or dihydrochloride).

Diluents suitable for implementing process (a) of the invention include all inert organic solvents. These include preferably aliphatic, alicyclic or aromatic hydrocarbons, such as petroleum ether, hexane, heptane, cyclohexane, methylcyclohexane, benzene, toluene, xylene or decalin, for example; halogenated hydrocarbons, such as chlorobenzene, dichlorobenzene, dichloromethane, chloroform, tetrachloromethane, dichloroethane or trichloroethane, for example; ethers, such as diethyl ether, diisopropyl ether, methyl tert-butyl ether, methyl tert-amyl ether, dioxane, tetrahydrofuran, 1,2-dimethoxyethane, 1,2-diethoxyethane or anisole; ketones, such as acetone, butanone, methyl isobutyl ketone or cyclohexanone; nitriles, such as acetonitrile, propionitrile, n- or isobutyronitrile or benzonitrile; amides, such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methylformanilide, N-methylpyrrolidone or hexamethylphosphortriamide; or mixtures thereof with water, or pure water. It is preferred to use tetrahydrofuran or mixtures of tetrahydrofuran with water.

The reaction temperatures when implementing process (a) of the invention may be varied within a relatively wide range. Generally speaking, operation takes place at temperatures between 0° C. and 200° C., preferably between 20° C. and 80° C.

When implementing process (a) of the invention, for each mole of pyridazinedione derivative of the formula (II), 0.8 to 2 mol, preferably 1 to 1.5 mol, of disodium (Z)-1,2-dicyanoethene-1,2-bis(thiolate) of the formula (III) are used.

Suitable diluents for implementing process (b) of the invention include water, dimethyl sulfoxide, sulfolane, alcohols such as methanol, ethanol, propanol, isopropanol, butanol, tert-butanol, cyclopentanol, cyclohexanol, ethylene glycol and ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, amides such as formamide, N,N-dimethylformamide; N,N-dimethylacetamide and N-methylpyrrolidone, ethers such as tetrahydrofuran and 1,4-dioxane, nitriles such as acetonitrile, propionitrile, butyronitrile and benzonitrile, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and pinacolone, or mixtures of these diluents.

The reaction temperatures when implementing process (b) of the invention may be varied within a relatively wide range. In general, operation takes place at temperatures between 0° C. and 200° C., preferably between 20° C. and 150° C.

When implementing process (b) of the invention, for each mole of pyridazinedione derivative of the formula (II), 0.4 to 1 mol, preferably 0.5 to 0.7 mol, of thiourea of the formula (IV) is used.

Suitable diluents for implementing process (c) of the invention include all inert organic solvents and also water. These include, preferably, alcohols, such as ethanol and methoxyethanol; ketones, such as 2-butanone; nitriles, such as acetonitrile; esters, such as ethyl acetate; ethers, such as dioxane; aromatic hydrocarbons, such as benzene and toluene; or amides, such as dimethylformamide, for example.

The reaction temperatures when implementing process (c) of the invention may be varied within a relatively wide range. In general, operation takes place at temperatures between 0° C. and 200° C., preferably between 20° C. and 150° C.

When implementing process (c) of the invention, for each mole of hydrazine derivatives of the formula (V), 0.8 to 2 mol, preferably 1 to 1.5 mol, of thiourea of the formula (IV) and/or of another sulfurizing agent (cf. above) are used.

The present invention relates, furthermore, to a crop protection composition for controlling unwanted fungi, comprising at least one of the dithiinopyridazinedione derivatives of the formula (I). The compositions in question are preferably fungicidal compositions which comprise agriculturally useful auxiliaries, solvents, carriers, surface-active substances or extenders.

The invention relates, moreover, to a method for controlling unwanted microorganisms, characterized in that, in accordance with the invention, dithiinopyridazinedione derivatives of the formula (I) are delivered to the phytopathogenic fungi and/or their habitat.

In accordance with the invention, “carrier” denotes a natural or synthetic, organic or inorganic substance with which the active compounds are joined or mixed for greater ease of application, including for application to plants or plant parts or seed. The carrier, which may be solid or liquid, is generally inert and ought to be suitable for use in agriculture.

Suitable solid or liquid carriers are: for example ammonium salts and ground natural minerals, such as kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth, and ground synthetic minerals, such as finely divided silica, alumina and natural or synthetic silicates, resins, waxes, solid fertilizers, water, alcohols, especially butanol, organic solvents, mineral and vegetable oils and derivatives of these. Mixtures of such carriers may also be used. Suitable solid carriers for granules are: for example crushed and fractionated natural minerals, such as calcite, marble, pumice, sepiolite, dolomite, and also synthetic granules of inorganic and organic meals and also granules of organic material, such as sawdust, coconut shells, maize cobs and tobacco stalks.

Suitable liquefied gaseous extenders or carriers are liquids which are gaseous at ambient temperature and under atmospheric pressure, for example aerosol propellants, such as halohydrocarbons, and also butane, propane, nitrogen and carbon dioxide.

Tackifiers, such as carboxymethylcellulose and natural and synthetic polymers in the form of powders, granules or latices, such as gum arabic, polyvinyl alcohol, polyvinyl acetate, or else natural phospholipids, such as cephalins and lecithins and synthetic phospholipids can be used in the formulations. Other possible additives are mineral and vegetable oils.

If the extender used is water, it is also possible, for example, to use organic solvents as auxiliary solvents. Suitable liquid solvents are essentially: aromatic compounds, such as xylene, toluene or alkylnaphthalenes, chlorinated aromatic compounds or chlorinated aliphatic hydrocarbons, such as chlorobenzenes, chloroethylenes or dichloromethane, aliphatic hydrocarbons, such as cyclohexane or paraffins, for example mineral oil fractions, mineral and vegetable oils, alcohols, such as butanol or glycol, and also ethers and esters thereof, ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, strongly polar solvents, such as dimethylformamide and dimethyl sulphoxide, and also water.

The compositions according to the invention may comprise additional further components, such as, for example, surface-active substances. Suitable surface-active substances are emulsifiers and/or foam-formers, dispersants or wetting agents having ionic or nonionic properties, or mixtures of these surface-active substances. Examples of these are salts of polyacrylic acid, salts of lignosulphonic acid, salts of phenolsulphonic acid or naphthalenesulphonic acid, polycondensates of ethylene oxide with fatty alcohols or with fatty acids or with fatty amines, substituted phenols (preferably alkylphenols or arylphenols), salts of sulphosuccinic esters, taurine derivatives (preferably alkyl taurates), phosphoric esters of polyethoxylated alcohols or phenols, fatty acid esters of polyols, and derivatives of the compounds containing sulphates, sulphonates and phosphates, for example, alkylaryl polyglycol ethers, alkylsuiphonates, alkyl sulphates, arylsulphonates, protein hydrolysates, ligno-sulphite waste liquors and methylcellulose. The presence of a surface-active substance is required if one of the active compounds and/or one of the inert carriers is insoluble in water and when the application takes place in water. The proportion of surface-active substances is between 5 and 40 percent by weight of the composition according to the invention.

It is possible to use colorants such as inorganic pigments, for example iron oxide, titanium oxide, Prussian blue, and organic dyes, such as alizarin dyes, azo dyes and metal phthalocyanine dyes, and trace nutrients, such as salts of iron, manganese, boron, copper, cobalt, molybdenum and zinc.

If appropriate, other additional components may also be present, for example protective colloids, binders, adhesives, thickeners, thixotropic substances, penetrants, stabilizers, sequestering agents, complex-formers. In general, the active compounds can be combined with any solid or liquid additive customarily used for formulation purposes.

In general, the formulations contain between 0.05 and 99% by weight, 0.01 and 98% by weight, preferably between 0.1 and 95% by weight, especially preferably between 0.5 and 90% by weight of active compound, very especially preferably between 10 and 70 percent by weight.

The active compounds or compositions according to the invention can be used as such or, depending on their respective physical and/or chemical properties, in the form of their formulations or the use forms prepared therefrom, such as aerosols, capsule suspensions, cold-fogging concentrates, warm-fogging concentrates, encapsulated granules, fine granules, flowable concentrates for the treatment of seed, ready-to-use solutions, dustable powders, emulsifiable concentrates, oil-in-water emulsions, water-in-oil emulsions, macrogranules, microgranules, oil-dispersible powders, oil-miscible flowable concentrates, oil-miscible liquids, foams, pastes, pesticide-coated seed, suspension concentrates, suspoemulsion concentrates, soluble concentrates, suspensions, wettable powders, soluble powders, dusts and granules, water-soluble granules or tablets, water-soluble powders for the treatment of seed, wettable powders, natural products and synthetic subtances impregnated with active compound, and also microencapsulations in polymeric substances and in coating materials for seed, and also ULV cold-fogging and warm-fogging formulations.

The formulations mentioned can be prepared in a manner known per se, for example by mixing the active compounds with at least one customary extender, solvent or diluent, emulsifier, dispersant and/or binder or fixing agent, wetting agent, water repellent, if appropriate siccatives and UV stabilizers and, if appropriate, dyes and pigments, defoamers, preservatives, secondary thickeners, adhesives, gibberellins and also further processing auxiliaries.

The compositions according to the invention do not only comprise ready-to-use formulations which can be applied with a suitable apparatus to the plant or the seed, but also commercial concentrates which have to be diluted with water prior to use.

The active compounds according to the invention, per se or in their (commercially available) formulations and in the use forms prepared from these formulations, may be present in a mixture with other (known) active compounds such as insecticides, attractants, sterilants, bactericides, acaricides, nematicides, fungicides, growth regulators, herbicides, fertilizers, safeners or semiochemicals.

The treatment according to the invention of the plants and plant parts with the active compounds or compositions is carried out directly or by action on their surroundings, habitat or storage space using customary treatment methods, for example by dipping, spraying, atomizing, irrigating, evaporating, dusting, fogging, broadcasting, foaming, painting, spreading-on, drenching, drip irrigating and, in the case of propagation material, in particular in the case of seeds, furthermore by dry seed treatment, by wet seed treatment, by slurry treatment, by incrusting, by coating with one or more coats, etc. It is furthermore possible to apply the active compounds by the ultra-low-volume method, or to inject the active compound preparation, or the active compound itself, into the soil.

The invention furthermore comprises a method for the treatment of seed.

The invention furthermore relates to seed which has been treated in accordance with one of the methods described in the previous paragraph. The seeds according to the invention are used in methods for the protection of seed from undesirable fungi. Here, a seed treated with at least one active compound according to the invention is used.

The active compounds or compositions according to the invention are also suitable for treating seed. A large part of the damage to crop plants caused by harmful organisms is triggered by the infection of the seed during storage or after sowing as well as during and after germination of the plant. This phase is particularly critical since the roots and shoots of the growing plant are particularly sensitive, and even just a small amount of damage may result in the death of the plant. Accordingly, there is great interest in protecting the seed and the germinating plant by using appropriate compositions.

The control of phytopathogenic fungi by treating the seed of plants has been known for a long time and is the subject of continuous improvements. However, the treatment of seed entails a series of problems which cannot always be solved in a satisfactory manner. Thus, it is desirable to develop methods for protecting the seed and the germinating plant which dispense with the additional application of crop protection compositions after sowing or after the emergence of the plants or which at least considerably reduce additional application. It is furthermore desirable to optimize the amount of active compound employed in such a way as to provide maximum protection for the seed and the germinating plant from attack by phytopathogenic fungi, but without damaging the plant itself by the active compound employed. In particular, methods for the treatment of seed should also take into consideration the intrinsic fungicidal properties of transgenic plants in order to achieve optimum protection of the seed and the germinating plant with a minimum of crop protection compositions being employed.

Accordingly, the present invention also relates to a method for protecting seed and germinating plants against attack by phytopathogenic fungi by treating the seed with a composition according to the invention. The invention also relates to the use of the compositions according to the invention for treating seed for protecting the seed and the germinating plant against phytopathogenic fungi. Furthermore, the invention relates to seed treated with a composition according to the invention for protection against phytopathogenic fungi.

The control of phytopathogenic fungi which damage plants post-emergence is carried out primarily by treating the soil and the above-ground parts of plants with crop protection compositions. Owing to the concerns regarding a possible impact of the crop protection compositions on the environment and the health of humans and animals, there are efforts to reduce the amount of active compounds applied.

One of the advantages of the present invention is that, because of the particular systemic properties of the active compounds or compositions according to the invention, treatment of the seed with these active compounds or compositions not only protects the seed itself, but also the resulting plants after emergence, from phytopathogenic fungi. In this manner, the immediate treatment of the crop at the time of sowing or shortly thereafter can be dispensed with.

It is also considered to be advantageous that the active compounds or compositions according to the invention can be used in particular also for transgenic seed where the plant growing from this seed is capable of expressing a protein which acts against pests. By treating such seed with the active compounds or compositions according to the invention, even by the expression of the, for example, insecticidal protein, certain pests may be controlled. Surprisingly, a further synergistic effect may be observed here, which additionally increases the effectiveness of the protection against attack by pests.

The compositions according to the invention are suitable for protecting seed of any plant variety employed in agriculture, in the greenhouse, in forests or in horticulture and viticulture. In particular, this takes the form of seed of cereals (such as wheat, barley, rye, triticale, sorghum/millet and oats), maize, cotton, soya beans, rice, potatoes, sunflower, bean, coffee, beet (for example sugar beet and fodder beet), peanut, oilseed rape, poppy, olive, coconut, cacao, sugar cane, tobacco, vegetables (such as tomato, cucumbers, onions and lettuce), turf and or -namentals (see also hereinbelow). Of particular importance is the treatment of the seed of cereals (such as wheat, barley, rye, triticale and oats), maize and rice.

As also described hereinbelow, the treatment of transgenic seed with the active compounds or compositions according to the invention is of particular importance. This refers to the seed of plants containing at least one heterologous gene which allows the expression of a polypeptide or protein having insecticidal properties. The heterologous gene in transgenic seed can originate, for example, from microorganisms of the species Bacillus, Rhizobium, Pseudomonas, Serratia, Trichoderma, Clavibacter, Glomus or Gliocladium. Preferably, this heterologous gene is from Bacillus sp., the gene product having activity against the European corn borer and/or the Western corn rootworm. Particularly preferably, the heterologous gene originates from Bacillus thuringiensis.

In the context of the present invention, the composition according to the invention is applied on its own or in a suitable formulation to the seed. Preferably, the seed is treated in a state in which it is sufficiently stable so that the treatment does not cause any damage. In general, treatment of the seed may take place at any point in time between harvesting and sowing. Usually, the seed used has been separated from the plant and freed from cobs, shells, stalks, coats, hairs or the flesh of the fruits. Thus, it is possible to use, for example, seed which has been harvested, cleaned and dried to a moisture content of less than 15% by weight. Alternatively, it is also possible to use seed which, after drying, has been treated, for example, with water and then dried again.

When treating the seed, care must generally be taken that the amount of the composition according to the invention applied to the seed and/or the amount of further additives is chosen in such a way that the germination of the seed is not adversely affected, or that the resulting plant is not damaged. This must be borne in mind in particular in the case of active compounds which may have phytotoxic effects at certain application rates.

The compositions according to the invention can be applied directly, that is to say without comprising further components and without having been diluted. In general, it is preferable to apply the compositions to the seed in the form of a suitable formulation. Suitable formulations and methods for the treatment of seed are known to the person skilled in the art and are described, for example, in the following documents: U.S. Pat. No. 4,272,417 A, U.S. Pat. No. 4,245,432 A, U.S. Pat. No. 4,808,430 A, U.S. Pat. No. 5,876,739 A, US 2003/0176428 A 1, WO 2002/080675 A 1, WO 2002/028186 A2.

The active compounds which can be used according to the invention can be converted into the customary seed-dressing product formulations such as solutions, emulsions, suspensions, powders, foams, slurries and other coating compositions for seed, and ULV formulations.

These formulations are prepared in the known manner by mixing the active compounds with customary additives such as, for example, customary extenders and also solvents or diluents, colorants, wetting agents, dispersants, emulsifiers, defoamer, preservatives, secondary thickeners, adhesives, gibberellins, and also water.

Colorants which may be present in the seed-dressing product formulations which can be used according to the invention are all colorants which are customary for such purposes. Both pigments, which are sparingly soluble in water, and dyes, which are soluble in water, may be used. Examples of colorants which may be mentioned are those known by the names Rhodamin B, C.1. Pigment Red 112 and C.1. Solvent Red 1.

Wetting agents which may be present in the seed-dressing product formulations which can be used according to the invention are all substances which are conventionally used for the formulation of agrochemical active compounds and for promoting wetting. Alkylnaphthalenesulphonates, such as diisopropyl- or diisobutylnaphthalenesulphonates, can preferably be used.

Suitable dispersants and/or emulsifiers which may be present in the seed-dressing product formulations which can be used in accordance with the invention are all non-ionic, anionic and cationic dispersants which are conventionally used for the formulation of agrochemical active compounds. Non-ionic or anionic dispersants or mixtures of non-ionic or anionic dispersants can preferably be used. Suitable non-ionic dispersants which may be mentioned are, in particular, ethylene oxide/propylene oxide block polymers, alkylphenol polyglycol ethers and tristryrylphenol polyglycol ethers, and their phosphated or sulphated derivatives. Suitable anionic dispersants are, in particular, lignosulphonates, polyacrylic acid salts and arylsulphonate/formaldehyde condensates.

Defoamers which may be present in the seed-dressing product formulations which can be used according to the invention are all foam-suppressing substances conventionally used for the formulation of agrochemical active compounds. Silicone defoamers and magnesium stearate can preferably be used.

Preservatives which may be present in the seed-dressing product formulations which can be used according to the invention are all substances which can be employed in agrochemical compositions for such purposes. Examples which may be mentioned are dichlorophene and benzyl alcohol hemiformal.

Secondary thickeners which may be present in the seed-dressing product formulations which can be used according to the invention are all substances which can be employed in agrochemical compositions for such purposes. Cellulose derivatives, acrylic acid derivatives, xanthan, modified clays and highly disperse silica are preferably suitable.

Adhesives which may be present in the seed-dressing product formulations which can be used according to the invention are all customary binders which can be employed in seed-dressing products. Polyvinylpyrrolidone, polyvinyl acetate, polyvinyl alcohol and tylose may be mentioned by preference.

Gibberellins which may be present in the seed-dressing product formulations which can be used according to the invention are preferably the gibberellins A1, A3 (=gibberellic acid), A4 and A7, with gibberellic acid being particularly preferably used. The gibberellins are known (cf. R. Wegler “Chemie der Pflanzenschutz- and Schädlingsbekämpfungsmittel” [Chemistry of Plant Protectants and Pesticides], Vol. 2, Springer Verlag, 1970, pp. 401-412).

The seed-dressing product formulations which can be used in accordance with the invention can be employed either directly or after previous dilution with water for the treatment of a wide range of seeds, including the seed of transgenic plants. In this context, additional synergistic effects may also occur as a consequence of the interaction with the substances formed by expression.

Suitable apparatuses which can be employed for treating seed with the seed-dressing product formulations which can be used in accordance with the invention, or with the preparations prepared therefrom by addition of water, are all mixing apparatuses which can usually be employed for dressing seed. Specifically, a seed-dressing procedure is followed in which the seed is placed in a mixer, the amount of seed-dressing product formulation desired in each case is added, either as such or after previously diluting it with water, and the contents of the mixer are mixed until the formulation has been distributed uniformly on the seed. If appropriate, this is followed by a drying process.

The active compounds or compositions according to the invention have a potent fungicidal activity and can be employed for controlling unwanted fungi in crop protection and in the protection of materials.

The dithiinopyridazinedione derivatives according to the invention can be used in crop protection for controlling Plasmodiophoromycetes, Oomycetes, Chytridiomycetes, Zygomycetes, Ascomycetes, Basidiomycetes and Deuteromycetes.

The fungicidal compositions according to the invention can be employed curatively or protectively for controlling phytopathogenic fungi. The invention therefore also relates to curative and protective methods of controlling phytopathogenic fungi by using the active compounds or compositions according to the invention, which are applied to the seed, the plant or plant parts, the fruits or the soil in which the plants grow.

The compositions according to the invention for controlling phytopathogenic fungi in plant protection comprise an effective, but nonphytotoxic, amount of the active compounds according to the invention. “Effective, but nonphytotoxic amount” means such an amount of the composition according to the invention which suffices for sufficiently controlling or fully eradicating the fungal disease of the plant while simultaneously not entailing substantial phytotoxicity symptoms. In general, this application rate can vary within a substantial range. It depends on a plurality of factors, for example on the fungus to be controlled, the plant, the climatic conditions and the constituents of the compositions according to the invention.

The good plant tolerance of the active compounds at the concentrations required for controlling plant diseases permits the treatment of aerial plant parts, of vegetative propagation material and of seed, and of the soil.

All plants and plant parts can be treated in accordance with the invention. In the present context, plants are understood as meaning all plants and plant populations, such as desired and undesired wild plants or crop plants (including naturally occurring crop plants). Crop plants can be plants which can be obtained by traditional breeding and optimization methods or by biotechnological and recombinant methods, or combinations of these methods, including the transgenic plants and including the plant varieties capable or not of being protected by Plant Breeders' Rights. Plant parts are understood as meaning all aerial and subterranean parts and organs of the plants, such as shoot, leaf, flower and root, examples which may be mentioned being leaves, needles, stalks, stems, flowers, fruiting bodies, fruits and seeds, and also roots, tubers and rhizomes. The plant parts also include the harvested material and vegetative and generative propagation material, for example cuttings, tubers, rhizomes, slips and seeds.

The active compounds according to the invention are suitable for the protection of plants and plant organs, for increasing the yields, for improving the quality of the harvested crop, while being well tolerated by plants, having favourable toxicity to warm-blooded species and being environmentally friendly. They can preferably be employed as crop protection compositions. They are active against normally sensitive and resistant species and against all or individual developmental stages.

Plants which can be treated in accordance with the invention and which may be mentioned are the following: cotton, flax, grapevine, fruit, vegetables, such as Rosaceae sp. (for example pome fruits such as apples and pears, but also stone fruits such as apricots, cherries, almonds and peaches, and soft fruits such as strawberries), Ribesioidae sp., Juglandaceae sp., Betulaceae sp., Anacardiaceae sp., Fagaceae sp., Moraceae sp., Oleaceae sp., Actinidaceae sp., Lauraceae sp., Musaceae sp. (for example banana plants and banana plantations), Rubiaceae sp. (for example coffee), Theaceae sp., Sterculiceae sp., Rutaceae sp. (for example lemons, oranges and grapefruit); Solanaceae sp. (for example tomatoes), Liliaceae sp., Asteraceae sp. (for example lettuce), Umbelliferae sp., Cruciferae sp., Chenopodiaceae sp., Cucurbitaceae sp. (for example cucumbers), Alliaceae sp. (for example leeks, onions), Papilionaceae sp. (for example peas); major crop plants such as Gramineae sp. (for example maize, turf, cereals such as wheat, rye, rice, barley, oats, sorghum, millet and triticale), Poaceae sp. (for example sugar cane), Asteraceae sp. (for example sunflower), Brassicaceae sp. (for example white cabbage, red cabbage, broccoli, cauliflower, Brussels sprouts, pak choi, kohlrabi, small radishes, and also oilseed rape, mustard, horseradish and cress), Fabacae sp. (for example beans, peanuts), Papilionaceae sp. (for example soya beans), Solanaceae sp. (for example potatoes), Chenopodiaceae sp. (for example sugar beet, fodder beet, Swiss chard, beetroot); useful plants and ornamental plants in gardens and forests; and in each case genetically modified types of these plants.

As has already been mentioned above, all plants and their parts may be treated in accordance with the invention. In a preferred embodiment, plant species and plant varieties, and their parts, which grow wild or which are Obtained by traditional biological breeding methods such as hybridization or protoplast fusion are treated. In a further preferred embodiment, transgenic plants and plant varieties which have been obtained by recombinant methods, if appropriate in combination with traditional methods (genetically modified organisms), and their parts are treated. The term “parts” or “parts of plants” or “plant parts” has been explained hereinabove. Plants of the plant varieties which are in each case commercially available or in use are especially preferably treated in accordance with the invention. Plant varieties are understood as meaning plants with novel traits which have been bred both by traditional breeding, by mutagenesis or by recombinant DNA techniques. They may take the form of varieties, subspecies, biotypes and genotypes.

The method of treatment according to the invention can be used in the treatment of genetically modified organisms (GMOs), e.g. plants or seeds. Genetically modified plants (or transgenic plants) are plants in which a heterologous gene has been stably integrated into the genome. The expression “heterologous gene” essentially means a gene which is provided or assembled outside the plant and when introduced in the nuclear, chloroplastic or mitochondrial genome gives the transformed plant new or improved agronomic or other properties by expressing a protein or polypeptide of interest or by downregulating or silencing other gene(s) which are present in the plant (using for example antisense technology, cosuppression technology or RNA interference—RNA i-technology). A heterologous gene that is located in the genome is also called a transgene. A transgene that is defined by its particular location in the plant genome is called a transformation or transgenic event.

Depending on the plant species or plant varieties, their location and growth conditions (soils, climate, vegetation period, diet), the treatment according to the invention may also result in superadditive (“synergistic”) effects. Thus, for example, reduced application rates and/or a widening of the activity spectrum and/or an increase in the activity of the active compounds and compositions which can be used according to the invention, better plant growth, increased tolerance to high or low temperatures, increased tolerance to drought or to water or soil salt content, increased flowering performance, easier harvesting, accelerated maturation, higher harvest yields, bigger fruits, larger plant height, greener leaf colour, earlier flowering, higher quality and/or a higher nutritional value of the harvested products, higher sugar concentration within the fruits, better storage stability and/or processability of the harvested products are possible, which effects exceed the effects which were actually to be expected.

At certain application rates, the active compound combinations according to the invention may also have a strengthening effect in plants. Accordingly, they are suitable for mobilizing the defence system of the plant against attack by unwanted phytopathogenic fungi and/or microorganisms and/or viruses. This may, if appropriate, be one of the reasons for the enhanced activity of the combinations according to the invention, for example against fungi. Plant-strengthening (resistance-inducing) substances are to be understood as meaning, in the present context, also those substances or combinations of substances which are capable of stimulating the defence system of plants in such a way that, when subsequently inoculated with unwanted phytopathogenic fungi, the treated plants display a substantial degree of resistance to these unwanted phytopathogenic fungi. Thus, the substances according to the invention can be employed for protecting plants against attack by the abovementioned pathogens within a certain period of time after the treatment. The period of time within which protection is effected generally extends from 1 to 10 days, preferably 1 to 7 days, after the treatment of the plants with the active compounds.

Plants and plant varieties which are preferably treated according to the invention include all plants which have genetic material which imparts particularly advantageous, useful traits to these plants (whether obtained by breeding and/or biotechnological means).

Plants and plant varieties which are also preferably to be treated according to the invention are resistant against one or more biotic stresses, i.e. said plants have a better defence against animal and microbial pests, such as against nematodes, insects, mites, phytopathogenic fungi, bacteria, viruses and/or viroids.

Plants and plant varieties which may also be treated according to the invention are those plants which are resistant to one or more abiotic stresses. Abiotic stress conditions may include, for example, drought, cold temperature exposure, heat exposure, osmotic stress, waterlogging, increased soil salinity, increased exposure to minerals, exposure to ozone, exposure to strong light, limited availability of nitrogen nutrients, limited availability of phosphorus nutrients or shade avoidance.

Plants and plant varieties which may also be treated according to the invention are those plants characterized by enhanced yield characteristics. Enhanced yield in said plants can be the result of, for example, improved plant physiology, growth and development, such as water use efficiency, water retention efficiency, improved nitrogen use, enhanced carbon assimilation, improved photosynthesis, increased germination efficiency and accelerated maturation. Yield can furthermore be affected by improved plant architecture (under stress and non-stress conditions), including early flowering, flowering control for hybrid seed production, seedling vigour, plant size, internode number and distance, root growth, seed size, fruit size, pod size, pod or ear number, seed number per pod or ear, seed mass, enhanced seed filling, reduced seed dispersal, reduced pod dehiscence and lodging resistance. Further yield traits include seed composition, such as carbohydrate content, protein content, oil content and composition, nutritional value, reduction in anti-nutritional compounds, improved processability and better storage stability.

Plants that may be treated according to the invention are hybrid plants that already express the characteristics of heterosis, or hybrid vigour, which results in generally higher yield, vigour, better health and resistance towards biotic and abiotic stress factors. Such plants are typically made by crossing an inbred male-sterile parent line (the female parent) with another inbred male-fertile parent line (the male parent). Hybrid seed is typically harvested from the male-sterile plants and sold to growers. Male-sterile plants can sometimes (e.g. in corn) be produced by detasseling (i.e. the mechanical removal of the male reproductive organs or male flowers) but, more typically, male sterility is the result of genetic determinants in the plant genome. In that case, and especially when seed is the desired product to be harvested from the hybrid plants, it is typically useful to ensure that male fertility in the hybrid plants, which contain the genetic determinants responsible for male sterility, is fully restored. This can be accomplished by ensuring that the male parents have appropriate fertility restorer genes which are capable of restoring the male fertility in hybrid plants that contain the genetic determinants responsible for male sterility. Genetic determinants for male sterility may be located in the cytoplasm. Examples of cytoplasmic male sterility (CMS) were for instance described for Brassica species. However, genetic determinants for male sterility can also be located in the nuclear genome. Male-sterile plants can also be obtained by plant biotechnology methods such as genetic engineering. A particularly useful means of obtaining male-sterile plants is described in WO 89/10396 in which, for example, a ribonuclease such as a barnase is selectively expressed in the tapetum cells in the stamens. Fertility can then be restored by expression in the tapetum cells of a ribonuclease inhibitor such as barstar.

Plants or plant cultivars (obtained by plant biotechnology methods such as genetic engineering) which may be treated according to the invention are herbicide-tolerant plants, i.e. plants made tolerant to one or more given herbicides. Such plants can be obtained either by genetic transformation, or by selection of plants containing a mutation imparting such herbicide tolerance.

Herbicide-tolerant plants are for example glyphosate-tolerant plants, i.e. plants made tolerant to the herbicide glyphosate or salts thereof. For example, glyphosate-tolerant plants can be obtained by transforming the plant with a gene encoding the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS). Examples of such EPSPS genes are the AroA gene (mutant CT7) of the bacterium Salmonella typhimurium, the CP4 gene of the bacterium Agrobacterium sp., the genes encoding a petunia EPSPS, a tomato EPSPS, or an Eleusine EPSPS. It can also be a mutated EPSPS. Glyphosate-tolerant plants can also be obtained by expressing a gene that encodes a glyphosate oxidoreductase enzyme. Glyphosate-tolerant plants can also be obtained by expressing a gene that encodes a glyphosate acetyltransferase enzyme. Glyphosate-tolerant plants can also be obtained by selecting plants containing naturally occurring mutations of the abovementioned genes.

Other herbicide-resistant plants are for example plants that are made tolerant to herbicides inhibiting the enzyme glutamine synthase, such as bialaphos, phosphinothricin or glufosinate. Such plants can be obtained by expressing an enzyme detoxifying the herbicide or a mutant glutamine synthase enzyme that is resistant to inhibition. One such efficient detoxifying enzyme is, for example, an enzyme encoding a phosphinothricin acetyltransferase (such as the bar or pat protein from Streptomyces species). Plants expressing an exogenous phosphinothricin acetyltransferase are described.

Further herbicide-tolerant plants are also plants that are made tolerant to the herbicides inhibiting the enzyme hydroxyphenylpyruvatedioxygenase (HPPD). Hydroxyphenylpyruvatedioxygenases are enzymes that catalyse the reaction in which para-hydroxyphenylpyruvate (HPP) is transformed into homogentisate. Plants tolerant to HPPD inhibitors can be transformed with a gene encoding a naturally occurring resistant HPPD enzyme, or a gene encoding a mutated HPPD enzyme. Tolerance to HPPD inhibitors can also be obtained by transforming plants with genes encoding certain enzymes enabling the formation of homogentisate despite the inhibition of the native HPPD enzyme by the HPPD inhibitor. Tolerance of plants to HPPD inhibitors can also be improved by transforming plants with a gene encoding an enzyme of prephenate dehydrogenase in addition to a gene encoding an HPPD-tolerant enzyme.

Further herbicide-resistant plants are plants that are made tolerant to acetolactate synthase (ALS) inhibitors. Known ALS inhibitors include, for example, sulphonylurea, imidazolinone, triazolopyrimidines, pyrimidinyloxy(thio)benzoates, and/or sulphonylaminocarbonyltriazolinone herbicides. Different mutations in the ALS enzyme (also known as acetohydroxyacid synthase, AHAS) are known to confer tolerance to different herbicides and groups of herbicides. The production of sulphonylurea-tolerant plants and imidazolinone-tolerant plants has been described in the international publication WO 1996/033270. Further sulphonylurea- and imidazolinone-tolerant plants have also been described, for example in WO 2007/024782.

Other plants tolerant to imidazolinone and/or sulphonylurea can be obtained by induced mutagenesis, selection in cell cultures in the presence of the herbicide or mutation breeding.

Plants or plant varieties (obtained by plant biotechnology methods such as genetic engineering) which may also be treated according to the invention are insect-resistant transgenic plants, i.e. plants made resistant to attack by certain target insects. Such plants can be obtained by genetic transformation, or by selection of plants containing a mutation imparting such insect resistance.

The term “insect-resistant transgenic plant”, as used herein, includes any plant containing at least one transgene comprising a coding sequence encoding:

1) an insecticidal crystal protein from Bacillus thuringiensis or an insecticidal portion thereof, such as the insecticidal crystal proteins listed online at: http://www.lifesci.sussex.ac.uk/Home/Neil_Crickmore/Bt/, or insecticidal portions thereof, e.g. proteins of the Cry protein classes Cry1Ab, Cry1Ac, Cry1F, Cry2Ab, Cry3Ae, or Cry3Bb or insecticidal portions thereof; or 2) a crystal protein from Bacillus thuringiensis or a portion thereof which is insecticidal in the presence of a second other crystal protein from Bacillus thuringiensis or a portion thereof, such as the binary toxin made up of the Cy34 and Cy35 crystal proteins; or 3) a hybrid insecticidal protein comprising parts of two different insecticidal crystal proteins from Bacillus thuringiensis, such as a hybrid of the proteins of 1) above or a hybrid of the proteins of 2) above, e.g. the CryIA.105 protein produced by maize event MON98034 (WO 2007/027777); or 4) a protein of any one of 1) to 3) above wherein some, particularly 1 to 10, amino acids have been replaced by another amino acid to obtain a higher insecticidal activity to a target insect species, and/or to expand the range of target insect species affected, and/or because of changes induced into the encoding DNA during cloning or transformation, such as the Cry3Bb1 protein in maize events MON863 or MON88017, or the Cry3A protein in maize event MIR 604; 5) an insecticidal secreted protein from Bacillus thuringiensis or Bacillus cereus, or an insecticidal portion thereof, such as the vegetative insecticidal proteins (VIP) listed at http://www.lifesci.sussex.ac.uk/Home/Neil_Crickmore/Bt/vip.html, e.g. proteins from the VIP3Aa protein class; or 6) a secreted protein from Bacillus thuringiensis or Bacillus cereus which is insecticidal in the presence of a second secreted protein from Bacillus thuringiensis or B. cereus, such as the binary toxin made up of the VIP1A and VIP2A proteins; 7) a hybrid insecticidal protein comprising parts from different secreted proteins from Bacillus thuringiensis or Bacillus cereus, such as a hybrid of the proteins in 1) above or a hybrid of the proteins in 2) above; or 8) a protein of any one of 1) to 3) above wherein some, particularly 1 to 10, amino acids have been replaced by another amino acid to obtain a higher insecticidal activity to a target insect species, and/or to expand the range of target insect species affected, and/or because of changes induced into the encoding DNA during cloning or trans-formation (while still encoding an insecticidal protein), such as the VIP3Aa protein in cotton event COT 102.

Of course, insect-resistant transgenic plants, as used herein, also include any plant comprising a combination of genes encoding the proteins of any one of the above classes 1 to 8. In one embodiment, an insect-resistant plant contains more than one transgene encoding a protein of any one of the above classes 1 to 8, to expand the range of target insect species affected or to delay development of insect resistance to the plants, by using different proteins insecticidal to the same target insect species but having a different mode of action, such as binding to different receptor binding sites in the insect.

Plants or plant varieties (obtained by plant biotechnology methods such as genetic engineering) which may also be treated according to the invention are tolerant to abiotic stresses. Such plants can be obtained by genetic transformation, or by selection of plants containing a mutation imparting such stress resistance. Particularly useful stress tolerance plants include:

a. plants which contain a transgene capable of reducing the expression and/or the activity of the poly(ADP-ribose)polymerase(PARP) gene in the plant cells or plants. b. plants which contain a stress tolerance-enhancing transgene capable of reducing the expression and/or the activity of the PARG-encoding genes of the plants or plant cells; c. plants which contain a stress tolerance-enhancing transgene coding for a plant-functional enzyme of the nicotinamide adenine dinucleotide salvage biosynthesis pathway, including nicotinamidase, nicotinate phosphoribosyltransferase, nicotinic acid mononucleotide adenyltransferase, nicotinamide adenine dinucleotide synthetase or nicotinamide phosphoribosyltransferase.

Plants or plant varieties (obtained by plant biotechnology methods such as genetic engineering) which may also be treated according to the invention show altered quantity, quality and/or storage stability of the harvested material and/or altered properties of specific ingredients of the harvested material such as:

1) transgenic plants which synthesize a modified starch, which in its physical-chemical characteristics, in particular the amylose content or the amylose/amylopectin ratio, the degree of branching, the average chain length, the side chain distribution, the viscosity behaviour, the gelling strength, the starch grain size and/or the starch grain morphology, is changed in comparison with the synthesized starch in wild type plant cells or plants, so that this modified starch is better suited for special applications. 2) transgenic plants which synthesize non-starch carbohydrate polymers or which synthesize non-starch carbohydrate polymers with altered properties in comparison to wild type plants without genetic modification. Examples are plants which produce polyfructose, especially of the inulin and levan type, plants which produce alpha-1,4-glucans, plants which produce alpha-1,6 branched alpha-1,4-glucans, and plants producing alternan. 3) transgenic plants which produce hyaluronan.

Plants or plant varieties (obtained by plant biotechnology methods such as genetic engineering) which may also be treated according to the invention are plants, such as cotton plants, with altered fibre characteristics.

Such plants can be obtained by genetic transformation, or by selection of plants containing a mutation imparting such altered fibre characteristics and include:

a) plants, such as cotton plants, which contain an altered form of cellulose synthase genes, b) plants, such as cotton plants, which contain an altered form of rsw2 or rsw3 homologous nucleic acids; c) plants, such as cotton plants, with an increased expression of sucrose phosphate synthase; d) plants, such as cotton plants, with an increased expression of sucrose synthase; e) plants, such as cotton plants, wherein the timing of the plasmodesmatal gating at the basis of the fibre cell is altered, e.g. through downregulation of fibre-selective β-1,3-glucanase; f) plants, such as cotton plants, which have fibres with altered reactivity, e.g. through the expression of the N-gene, including nodC, and chitin synthase genes.

Plants or plant varieties (obtained by plant biotechnology methods such as genetic engineering) which may also be treated according to the invention are plants, such as oilseed rape or related Brassica plants, with altered oil profile characteristics. Such plants can be obtained by genetic transformation or by selection of plants containing a mutation imparting such altered oil characteristics and include:

a) plants, such as oilseed rape plants, which produce oil having a high oleic acid content; b) plants, such as oilseed rape plants, which produce oil having a low linolenic acid content; c) plants, such as oilseed rape plants, which produce oil having a low level of saturated fatty acids.

Particularly useful transgenic plants which may be treated according to the invention are plants which comprise one or more genes which encode one or more toxins and are the following which are sold under the trade names YIELD GARD® (for example maize, cotton, soya beans), KnockOut® (for example maize), BiteGard® (for example maize), BT-Xtra® (for example maize), StarLink® (for example maize), Bollgard® (cotton), Nucotn® (cotton), Nucotn 33B® (cotton), NatureGard® (for example maize), Protecta® and NewLeaf® (potato). Examples of herbicide-tolerant plants which may be mentioned are maize varieties, cotton varieties and soya bean varieties which are sold under the trade names Roundup Ready® (tolerance to glyphosate, for example maize, cotton, soya beans), Liberty Link® (tolerance to phosphinothricin, for example oilseed rape), IMI® (tolerance to imidazolinone) and SCS® (tolerance to sulphonylurea, for example maize). Herbicide-resistant plants (plants bred in a conventional manner for herbicide tolerance) which may be mentioned include the varieties sold under the name Clearfield® (for example maize).

Particularly useful transgenic plants which may be treated according to the invention are plants containing transformation events, or a combination of transformation events, that are listed for example in the databases for various national or regional regulatory agencies (see for example http://gmoinfor.jrc.it/gmp_browse.aspx and http://www.agbios.com/dbase.php).

The active compounds or compositions according to the invention may furthermore be employed in the protection of materials for protecting industrial materials against attack and destruction by undesired microorganisms such as, for example, fungi.

In the present context, industrial materials are understood as meaning nonliving materials which have been prepared for use in industry. Industrial materials which are intended to be protected by active compounds according to the invention from fungal change or destruction can be, for example, glues, sizes, paper, wall card and board, textiles, carpets, leather, wood, paints and plastic articles, cooling lubricants and other materials which arc capable of being attacked or decomposed by microorganisms. Other materials to be protected and which can be adversely affected by the multiplication of microorganisms which may be mentioned within the scope are parts of production plants and buildings, for example cooling water circuits, cooling and heating systems and aeration and airconditioning units. Industrial materials which may be mentioned by preference within the scope of the present invention are glues, sizes, paper and boards, leather, wood, paints, cooling lubricants and heat-transfer fluids, especially preferably wood. The active compounds or compositions according to the invention can prevent disadvantageous effects such as rotting, decay, discolouration, decolouration or mould development. Moreover, the compounds according to the invention can be employed for protecting objects against being covered with growth, in particular ships' hulls, sieves, nets, buildings, jetties and signal units, which come into contact with seawater or brackish water.

The method according to the invention for controlling unwanted fungi can also be employed for protecting storage goods. Here, storage goods are to be understood as meaning natural substances of vegetable or animal origin or processed products thereof of natural origin, for which long-term protection is desired. Storage goods of vegetable origin, such as, for example, plants or plant parts, such as stems, leaves, tubers, seeds, fruits, grains, can be protected in the freshly harvested state or after processing by (pre)drying, moistening, comminuting, grinding, pressing or roasting. Storage goods also include timber, both unprocessed, such as construction timber, electricity poles and barriers, or in the form of finished products, such as furniture. Storage goods of animal origin are, for example, pelts, leather, furs and hairs. The active compounds according to the invention can prevent disadvantageous effects, such as rotting, decay, discolouration, decolouration or the development of mould.

Some pathogens of fungal diseases which can be treated according to the invention may be mentioned, by way of example, but not by way of limitation:

Diseases caused by powdery mildew pathogens, such as, for example, Blumeria species, such as, for example, Blumeria graminis; Podosphaera species, such as, for example, Podosphaera leucotricha; Sphaerotheca species, such as, for example, Sphaerotheca fuliginea; Uncinula species, such as, for example, Uncinula necator; Diseases caused by rust disease pathogens, such as, for example, Gymnosporangium species, such as, for example, Gymnosporangium sabinae; Hemileia species, such as, for example, Hemileia vastatrix; Phakopsora species, such as, for example, Phakopsora pachyrhizi and Phakopsora meibomiae; Puccinia species, such as, for example, Puccinia recondita or Puccinia triticina; Uromyces species, such as, for example, Uromyces appendiculatus;

Diseases caused by pathogens from the group of the Oomycetes, such as, for example, Bremia species, such as, for example, Bremia lactucae; Peronospora species, such as, for example, Peronospora pisi or P. brassicae; Phytophthora species, such as, for example, Phytophthora infestans; Plasmopara species, such as, for example, Plasmopara viticola; Pseudoperonospora species, such as, for example, Pseudoperonospora humuli or Pseudoperonospora cubensis; Pythium species, such as, for example, Pythium ultimum;

Leaf blotch diseases and leaf wilt diseases caused, for example, by Alternaria species, such as, for example, Alternaria solani; Cercospora species, such as, for example, Cercospora beticola; Cladiosporum species, such as, for example, Cladiosporium cucumerinum; Cochliobolus species, such as, for example, Cochliobolus sativus (conidia form: Drechslera, Syn: Helminthosporium); Colletotrichum species, such as, for example, Colletotrichum lindemuthanium; Cycloconium species, such as, for example, Cycloconium oleaginum; Diaporthe species, such as, for example, Diaporthe citri; Elsinoe species, such as, for example, Elsinoe fawcettii; Gloeosporium species, such as, for example, Gloeosporium laeticolor; Glomerella species, such as, for example, Glomerella cingulata; Guignardia species, such as, for example, Guignardia bidwelli; Leptosphaeria species, such as, for example, Leptosphaeria maculans; Magnaporthe species, such as, for example, Magnaporthe grisea; Microdochium species, such as, for example, Microdochium nivale; Mycosphaerella species, such as, for example, Mycosphaerella graminicola and M. fijiensis; Phaeosphaeria species, such as, for example, Phaeosphaeria nodorum; Pyrenophora species, such as, for example, Pyrenophora teres; Ramularia species, such as, for example, Ramularia collo-cygni; Rhynchosporium species, such as, for example, Rhynchosporium secalis; Septoria species, such as, for example, Septoria apii; Typhula species, such as, for example, Typhula incamata; Venturia species, such as, for example, Venturia inaequalis;

Root and stem diseases caused, for example, by Corticium species, such as, for example, Corticium graminearum; Fusarium species, such as, for example, Fusarium oxysporum; Gaeumannomyces species, such as, for example, Gaeumannomyces graminis; Rhizoctonia species, such as, for example, Rhizoctonia solani; Tapesia species, such as, for example, Tapesia acuformis; Thielaviopsis species, such as, for example, Thielaviopsis basicola;

Ear and panicle diseases (including maize cobs) caused, for example, by Alternaria species, such as, for example, Alternaria spp.; Aspergillus species, such as, for example, Aspergillus flavus; Cladosporium species, such as, for example, Cladosporium cladosporioides; Claviceps species, such as, for example, Claviceps purpurea; Fusarium species, such as, for example, Fusarium culmorum; Gibberella species, such as, for example, Gibberella zeae; Monographella species, such as, for example, Monographella nivalis; Septoria species, such as, for example, Septoria nodorum;

Diseases caused by smut fungi, such as, for example, Sphacelotheca species, such as, for example, Sphacelotheca reiliana; Tilletia species, such as, for example, Tilletia caries, T. controversa; Urocystis species, such as, for example, Urocystis occulta; Ustilago species, such as, for example, Ustilago nuda, U. nuda tritici;

Seed- and soil-borne rot and wilt diseases, and also diseases of seedlings, caused, for example, by Fusarium species, such as, for example, Fusarium culmorum; Phytophthora species, such as, for example, Phytophthora cactorum; Pythium species, such as, for example, Pythium ultimum; Rhizoctonia species, such as, for example, Rhizoctonia solani; Sclerotium species, such as, for example, Sclerotium rolfsii;

Verticilium species, such as, for example, Verticilium alboatrum;

Seed- and soil-borne rot and wilt diseases, and also diseases of seedlings, caused, for example, by Fusarium species, such as, for example, Fusarium culmorum; Phytophthora species, such as, for example, Phytophthora cactorum; Pythium species, such as, for example, Pythium ultimum; Rhizoctonia species, such as, for example, Rhizoctonia solani; Sclerotium species, such as, for example, Sclerotium rolfsii; Cancerous diseases, galls and witches' broom caused, for example, by Nectria species, such as, for example, Nectria galligena;

Wilt diseases caused, for example, by Monilinia species, such as, for example, Monilinia laxa;

Deformations of leaves, flowers and fruits caused, for example, by Taphrina species, such as, for example, Taphrina deformans;

Degenerative diseases of woody plants caused, for example, by Esca species, such as, for example, Phaemoniella clamydospora and Phaeoacremonium aleophilum and Fomitiporia mediterranea;

Diseases of flowers and seeds caused, for example, by Botrytis species, such as, for example, Botrytis cinerea; Diseases of plant tubers caused, for example, by Rhizoctonia species, such as, for example, Rhizoctonia solani; Helminthosporium species, such as, for example, Helminthosporium solani;

Diseases caused by bacteriopathogens, such as, for example, Xanthomonas species, such as, for example, Xanthomonas campestris pv. oryzae; Pseudomonas species, such as, for example, Pseudomonas syringae pv. lachrymans; Erwinia species, such as, for example, Erwinia amylovora.

Preference is given to controlling the following diseases of soya beans:

Fungal diseases on leaves, stems, pods and seeds caused, for example, by alternaria leaf spot (Alternaria spec. atrans tenuissima), anthracnose (Colletotrichum gloeosporoides dematium var. truncatum), brown spot (Septoria glycines), cercospora leaf spot and blight (Cercospora kikuchii), choanephora leaf blight (Choanephora infundibulifera trispora (Syn.)), dactuliophora leaf spot (dactuliophora glycines), downy mildew (Peronospora manshurica), drechslera blight (Drechslera glycini), frogeye leaf spot (Cercospora sojina), leptosphaerulina leaf spot (Leptosphaerulina trifolii), phyllostica leaf spot (Phyllosticta sojaecola), pod and stem blight (Phomopsis sojae), powdery mildew (Microsphaera diffusa), pyrenochaeta leaf spot (Pyrenochaeta glycines), rhizoctonia aerial, foliage, and web blight (Rhizoctonia solani), rust (Phakopsora pachyrhizi, Phakopsora meibomiae), scab (Sphaceloma glycines), stemphylium leaf blight (Stemphylium botryosum), target spot (Corynespora cassiicola).

Fungal diseases on roots and the stem base caused, for example, by black root rot (Calonectria crotalariae), charcoal rot (Macrophomina phaseolina), fusarium blight or wilt, root rot, and pod and collar rot (Fusarium oxysporum, Fusarium orthoceras, Fusarium semitectum, Fusarium equiseti), mycoleptodiscus root rot (Mycoleptodiscus terrestris), neocosmospora (Neocosmopspora vasinfecta), pod and stem blight (Diaporthe phaseolorum), stem canker (Diaporthe phaseolorum var. caulivora), phytophthora rot (Phytophthora megasperma), brown stem rot (Phialophora gregata), pythium rot (Pythium aphanidermatum, Pythium irregulare, Pythium debaryanum, Pythium myriotylum, Pythium ultimum), rhizoctonia root rot, stem decay, and damping-off (Rhizoctonia solani), sclerotinia stem decay (Sclerotinia sclerotiorum), sclerotinia Southern blight (Sclerotinia rolfsii), thielaviopsis root rot (Thielaviopsis basicola).

Organisms which can bring about degradation or modification of the industrial materials and which may be mentioned are fungi. The active compounds according to the invention are preferably active against fungi, in particular moulds, wood-discolouring and wood-destroying fungi (Basidiomycetes). Fungi of the following genera may be mentioned by way of example: Alternaria, such as Alternaria tenuis; Aspergillus, such as Aspergillus niger, Chactomium, such as Chaetomium globosum; Coniophora, such as Coniophora puetana; Lentinus, such as Lentinus tigrinus; Penicillium, such as Penicillium glaucum; Polyporus, such as Polyporus versicolor; Aureobasidium, such as Aureobasidium pullulans; Sclerophoma, such as Sclerophoma pityophila; Trichoderma, such as Trichoderma viride.

In addition, the active compounds of the invention also exhibit very good antimycotic activities. They possess a very broad antimycotic activity spectrum, in particular against dermatophytes and yeasts, moulds and diphasic fungi (e.g. against Candida species such as Candida albicans, Candida glabrata) and also epidermophyton floccosum, Aspergillus species such as Aspergillus niger and Aspergillus fumigatus, Trichophyton species such as Trichophyton mentagrophytes, Microsporon species such as Microsporon canis and audouinii. The recitation of these fungi by no means places any restriction on the mycotic spectrum which can be covered, but is only for illustration.

When employing the active compounds according to the invention as fungicides, the application rates may vary within a substantial range, depending on the type of application. The application rate of the active compounds according to the invention is

when treating plant parts, for example leaves: from 0.1 to 10 000 g/ha, preferably from 10 to 1000 g/ha, particularly preferably from 50 to 300 g/ha (when the application is carried out by watering or dropwise, it may even be possible to reduce the application rate, in particular when inert substrates such as rock wool or perlite are used); when treating seed: from 2 to 200 g per 100 kg of seed, preferably from 3 to 150 g per 100 kg of seed, especially preferably from 2.5 to 25 g per 100 kg of seed, very especially preferably from 2.5 to 12.5 g per 100 kg of seed; when treating the soil: from 0.1 to 10 000 g/ha, preferably from 1 to 5000 g/ha.

These application rates are mentioned only by way of example and not by way of limitation in the sense of the invention.

The active compounds or compositions according to the invention can thus be employed for protecting plants for a certain period of time after treatment against attack by the pathogens mentioned. The period for which protection is provided extends generally for 1 to 28 days, preferably 1 to 14 days, particularly preferably 1 to days, very particularly preferably 1 to 7 days after the treatment of the plants with the active compounds, or up to 200 days after the treatment of seed.

In addition, by the treatment according to the invention it is possible to reduce the mycotoxin content in the harvested material and the foodstuffs and feedstuffs prepared therefrom. Particular, but not exclusive, mention may be made here of the following mycotoxins: deoxynivalenol (DON), nivalenol, 15-Ac-DON, 3-Ac-DON, T2- and HT2-toxin, fumonisine, zearalenon, moniliformin, fusarin, diaceotoxyscirpenol (DAS), beauvericin, enniatin, fusaroproliferin, fusarenol, ochratoxins, patulin, ergot alkaloids and aflatoxins produced, for example, by the following fungi: Fusarium spec., such as Fusarium acuminatum, F. avenaceum, F. crookwellense, F. culmorum, F. graminearum (Gibberella zeae), F. equiseti, F. fujikoroi, F. musarum, F. oxysponun, F. proliferatum, F. poae, F. pseudograminearum, F. sambucinum, F. scirpi, F. semitectum, F. solani, F. sporotrichoides, F. langsethiae, F. subglutinans, F. tricinctum, F. verticillioides, etc., and also by Aspergillus spec., Penicillium spec., Claviceps purpurea, Stachybotrys spec., etc.

The abovementioned plants can be treated especially advantageously in accordance with the invention with the dithiinopyridazinedione derivatives of the formula (I) or the compositions according to the invention. The preferred ranges indicated above for the active compounds or compositions also apply to the treatment of these plants. The treatment of plants with the compounds or compositions mentioned specifically in the present text should be especially emphasized.

PREPARATION EXAMPLES

An amount of 1 g (4.254 mmol) of 2,3-dichloro-6,7,8,9-tetrahydropyridazino[1,2-a]pyridazine-1,4-dione (II-1) is introduced in 20 ml of absolute tetrahydrofuran. Subsequently 0.869 g (4.254 mmol) of disodium (Z)-1,2-dicyanoethene-1,2-bis(thiolate) and 2 ml of water are added and the mixture is stirred at 40° C. for 18 hours. It is filtered with suction and extracted with methylene chloride and water, and the extract is dried and concentrated. Chromatography on silica gel (cyclohexane/ethyl acetate 0-100%) gives 0.5 g (99% purity, 38.3% of theory) of 5,12-dioxo-5,7,8,9,10,12-hexahydro[1,4]dithiino[2,3-d]pyridazino[1,2-a]pyridazine-2,3-dicarbonitrile.

Preparation of Starting Materials of the Formula (II)

An amount of 8.907 g (56 mmol) of hexahydropyridazine dihydrochloride in 25 ml of water is admixed slowly with 9.349 g (56 mmol) of dichloromaleic anhydride. The mixture is stirred at room temperature for 1 hour and then under reflux for 12 hours. After the mixture has cooled, the crystals obtained are isolated by filtration with suction. This gives 11.87 g (99% purity, 89.3% of theory) of 2,3-dichloro-6,7,8,9-tetrahydropyridazino[1,2-a]pyridazine-1,4-dione.

In analogy to the examples above and also in accordance with the general descriptions of the processes according to the invention, the compounds of the formula (I) and (I-a) and (1-b) that are given in Table 1 below can be obtained.

TABLE 1 (I)

(I-a)

(I-b)

Compound Type R¹ R² R³ R⁴ R⁵ R⁶ Log P 1 (I-a) CN CN Me Me — — 1.39 2 (I-a) CN CN —(CH₂)₄— — — 1.74 3 (I-a) CN CN Et Et — — 2.05 4 (I-a) CN CN Pr Pr — — 2.80 5 (I-a) CN CN Et Pr — — 2.46 6 (I-a) CN CN —(CH₂)₂—O—(CH₂)₂— — — 1.51 7 (I-a) CN CN Me Pr — — 2.08 8 (I-a) CN CN —(CH₂)₃— — — 1.20 9 (I-a) CN CN Me Et — — 1.72 10  (I-b) — — Me Me Me Me 0.74 Me = methyl, Et = ethyl, Pr = n-propyl, CN = cyano

The logP values reported in the preparation examples and tables above are determined in accordance with EEC Directive 79/831 Annex V.A8 by means of HPLC (High Performance Liquid Chromatography) on a reversed-phase column (C18). Temperature: 43° C.

The determination with the LC-MS in the acidic range takes place at a pH of 2.7 using 0.1% aqueous formic acid and acetonitrile (containing 0.1% formic acid) as eluents; linear gradient from 10% acetonitrile to 95% acetonitrile.

Calibration takes place using unbranched alkan-2-ones (having 3 to 16 carbon atoms) of which the logP values are known (logP values determined on the basis of the retention times, by linear interpolation between two successive alkanones). The lambda-max values were determined on the basis of the UV spectra from 200 nm to 400 nm in the maxima of the chromatographic signals.

USE EXAMPLES Example A Alternaria Test (Tomato)/Protective

Solvent: 49 parts by weight of N,N-dimethylformamide Emulsifier: 1 part by weight of alkylaryl polyglycol ether

An appropriate preparation of active compound is produced by mixing 1 part by weight of active compound with the stated amounts of solvent and emulsifier and diluting the concentrate with water to the desired concentration. To test for protective activity, young tomato plants are sprayed with the preparation of active compound at the stated application rate. A day after the treatment, the plants are inoculated with a spore suspension of Alternaria solani and then stand for 24 hours at 100% relative humidity and 22° C. Subsequently the plants stand at 96% relative humidity and a temperature of 20° C. After 7 days following inoculation, evaluation takes place. Here, 0% denotes an efficacy which corresponds to that of the control, whereas an efficacy of 100% means that no infestation is observed. In this test, the following compounds according to the invention exhibit an efficacy of 70% or more at an active compound concentration of 1500 ppm.

TABLE A Alternaria test (tomato)/protective Active compound Application rate example in ppm Efficacy in % 2 1500 93 3 1500 86 4 1500 93 5 1500 93 6 1500 86 7 1500 93 8 1500 86 9 1500 86

Example B Phvtophthora Test (Tomato)/Protective

Solvent: 49 parts by weight of N,N-dimethylformamide Emulsifier: 0.1 part by weight of alkylaryl polyglycol ether

An appropriate preparation of active compound is produced by mixing 1 part by weight of active compound with the stated amounts of solvent and emulsifier and diluting the concentrate with water to the desired concentration. To test for protective activity, young tomato plants are sprayed with the preparation of active compound at the stated application rate. A day after the treatment, the plants are inoculated with a spore suspension of Phytophthora infestans and then stand for 24 hours at 100% relative humidity and 22° C. Subsequently the plants are placed in a controlled-climate cell at approximately 96% relative humidity and at a temperature of approximately 20° C. After 7 days following inoculation, evaluation takes place. Here, 0% denotes an efficacy which corresponds to that of the control, whereas an efficacy of 100% means that no infestation is observed. In this test, the following compounds according to the invention exhibit an efficacy of 70% or more at an active compound concentration of 1500 ppm.

TABLE B Phytophthora test (tomato)/protective Active compound Application rate example in ppm Efficacy in % 2 1500 88 3 1500 75 4 1500 94 5 1500 94 6 1500 75 7 1500 88 8 1500 75 9 1500 94

Example C Plasmopara Test (Grapevine)/Protective

Solvents: 24.5 parts by weight of acetone

-   -   24.5 parts by weight of dimethylacetamide         Emulsifier: 1 part by weight of alkylaryl polyglycol ether

An appropriate preparation of active compound is produced by mixing 1 part by weight of active compound with the stated amounts of solvent and emulsifier and diluting the concentrate with water to the desired concentration. To test for protective activity, young plants are sprayed with the preparation of active compound at the stated application rate. After the spray coating has dried on, the plants are inoculated with an aqueous spore suspension of Plasmopara viticola and then spend 1 day in an incubation cabin at approximately 20° C. and 100% relative humidity. Subsequently the plants are placed for 4 days in a greenhouse at approximately 21° C. and approximately 90% humidity. The plants are then moistened and placed in an incubation cabin for 1 day. After 6 days following inoculation, evaluation takes place. Here, 0% denotes an efficacy which corresponds to that of the control, whereas an efficacy of 100% means that no infestation is observed. In this test, the following compounds according to the invention exhibit an efficacy of 70% or more at an active compound concentration of 250 ppm.

TABLE C Plasmopara test (grapevine)/protective Active compound Application rate example in ppm Efficacy in % 2 250 100 5 250 95 9 250 93

Example D Puccinia Test (Wheat)/Protective

Solvent: 49 parts by weight of N,N-dimethylformamide Emulsifier: 1 part by weight of alkylaryl polyglycol ether

An appropriate preparation of active compound is produced by mixing 1 part by weight of active compound with the stated amounts of solvent and emulsifier and diluting the concentrate with water to the desired concentration. To test for protective activity, young wheat plants are sprayed with the preparation of active compound at the stated application rate. A day after the treatment, the plants are inoculated with a spore suspension of Puccinia recondita and then spend 48 hours at 100% relative humidity and 22° C. Subsequently the plants stand at 80% relative humidity and at a temperature of 20° C. After 7-9 days following inoculation, evaluation takes place. Here, 0% denotes an efficacy which corresponds to that of the control, whereas an efficacy of 100% means that no infestation is observed. In this test, the following compounds according to the invention exhibit an efficacy of 70% or more at an active compound concentration of 1500 ppm.

TABLE D Puccinia test (wheat)/Protective Active compound Application rate Efficacy Example No. in ppm in % 1 1500 90 2 1500 95 3 1500 95 4 1500 95 5 1500 95 6 1500 95 7 1500 80 8 1500 95 9 1500 95

Example E Venturia Test (Apple)/Protective

Solvents: 24.5 parts by weight of acetone

-   -   24.5 parts by weight of dimethylacetamide         Emulsifier: 1 part by weight of alkylaryl polyglycol ether

An appropriate preparation of active compound is produced by mixing 1 part by weight of active compound with the stated amounts of solvent and emulsifier and diluting the concentrate with water to the desired concentration. To test for protective activity, young plants are sprayed with the preparation of active compound at the stated application rate. After the spray coating has dried on, the plants are inoculated with an aqueous conidia suspension of the causative organism of apple scab, Venturia inaequalis, and then spend 1 day in an incubation cabin at approximately 20° C. and 100% relative humidity. Subsequently the plants are placed in a greenhouse at approximately 21° C. and approximately 90% humidity. After 10 days following inoculation, evaluation takes place. Here, 0% denotes an efficacy which corresponds to that of the control, whereas an efficacy of 100% means that no infestation is observed. In this test, the following compounds according to the invention exhibit an efficacy of 70% or more at an active compound concentration of 250 ppm.

TABLE E Venturia test (apple)/protective Active compound Application rate example in ppm Efficacy in % 2 250 89 5 250 95 9 250 86 

1. A dithiinopyridazinedione derivative of formula (I)

in which R¹ and R² either simultaneously are cyano or together are the group —C(═O)—N(R⁵)—N(R⁶)−C(═O)—, whereby the compounds compound of the formula (I) comprises a second pyridazinedione ring, R³, R⁴, R⁵ and R⁶ are identical or different and are hydrogen, or are C₁-C₈-alkyl optionally substituted one or more times by halogen, —OR⁷ or —OR⁸, or arc C₃-C₇-cycloalkyl optionally substituted one or more times by halogen, C₁-C₄-alkyl or C₁-C₄-haloalkyl, or are aryl or aryl-(C₁-C₄-alkyl) each optionally substituted one or more times by halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl or —OR⁸, R³ and R⁴ also together are C₃-C₈-alkylene (alkanediyl), C₃-C₆-alkoxyalkylene or C₃-C₆-alkylthioalkylene, R⁵ and R⁶ also together are C₃-C₈-alkylene (alkanediyl), C₃-C₆-alkoxyalkylene or C₃-C₆-alkylthioalkylene, R⁷ is hydrogen, C₁-C₄-alkyl or C₁-C₄-alkylcarbonyl or is aryl optionally substituted one or more times by halogen, C₁-C₄-alkyl or C₁-C₄-haloalkyl, and R⁸ is hydroxyl, C₁-C₄-alkyl or C₁-C₄-alkoxy.
 2. A dithiinopyridazinedione derivative of formula (I-a)

in which R³ and R⁴ are identical or different and are hydrogen, or are C₁-C₈-alkyl optionally substituted one or more times by halogen, —OR⁷ or —OR⁸, or are C₃-C₇cycloalkyl optionally substituted one or more times by halogen, C₁-C₄-alkyl or C₁-C₄-haloalkyl, or are aryl or aryl-(C₁-C₄-alkyl) each optionally substituted one or more times by halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl or —OR⁸, R³ and R⁴ also together are C3-C5-alkylene (alkanediyl), C₃-C₆-alkoxyalkylene or C₃-C₆-alkylthioalkylene, R⁷ is hydrogen, C₁-C₄-alkyl or C₁-C₄-alkylcarbonyl, or is aryl optionally substituted one or more times by halogen, C₁-C₄-alkyl or C₁-C₄-haloalkyl, and R⁸ is hydroxyl, C₁-C₄-alkyl or C₁-C₄-alkoxy.
 3. A dithiinopyridazinedione derivative of formula (I-b)

in which R³, R⁴, R⁵ and R⁶ are identical or different and are hydrogen, or are C₁-C₈-alkyl optionally substituted one or more times by halogen, —OR⁷ or —OR⁸, or are C₃-C₇-cycloalkyl optionally substituted one or more times by halogen, C₁-C₄-alkyl or C₁-C₄-haloalkyl, or are aryl or aryl-(C₁-C₄-alkyl) each optionally substituted one or more times by halogen, C₁-C₄-alkyl, C₁-C₄-haloalkyl or —OR^(E), R³ and R⁴ also together are C3-C5-alkylene (alkanediyl), C₃-C₆-alkoxyalkylene or C₃-C₆-alkylthioalkylene, R⁵ and R⁶ also together are C3-C5-alkylene (alkanediyl), C₃-C₆-alkoxyalkylene or C₃-C₆-alkylthioalkylene, R⁷ is hydrogen, C₁-C₄-alkyl or C₁-C₄-alkylcarbonyl or is aryl optionally substituted one or more times by halogen, C₁-C₄-alkyl or C₁-C₄-haloalkyl, and R⁸ is hydroxyl, C₁-C₄-alkyl or C₁-C₄-alkoxy.
 4. Compositions A composition for controlling unwanted microorganisms, comprising at least one dithiinopyridazinedione derivative of formula (I) according to claim 1 and extenders, surface-active substances or a combination thereof.
 5. (canceled)
 6. A method for protecting plants or materials form phytopathogenic fungi, comprising administering the dithiinopyridazinedione derivative of formula (I) according to claim 1 to the plants, parts of the plants, or the materials in need of such treatment.
 7. A method for controlling unwanted microorganisms, comprising administering the dithiinopyridazinedione derivative of formula (I) according to claim 1 are to the microorganisms, their habitat or a combination thereof.
 8. A process for producing a composition for controlling unwanted microorganisms, comprising mixing the dithiinopyridazinedione derivative of formula (I) according to claim 1 with one or more extenders, surface-active substances or a combination thereof.
 9. A method for treating a transgenic plant, comprising administering a dithiinopyridazinedione derivative of formula (I) according to claim 1 to the transgenic plant.
 10. A composition comprising at least one dithiinopyridazinedione derivative of formula (I) according to claim 1 and also at least one other active compound selected from the group consisting of insecticides, attractants, sterilants, bactericides, acaricides, nematicides, fungicides, growth regulators, herbicides, fertilizers, safeners and semiochemicals. 